The present invention relates to a process and apparatus for producing coke, asphalt and jet fuel from fossil fuels containing volatile carbon compounds therein. More particularly, the present process employs an entrained bed pyrolyzer for the purpose of producing coke, asphalt and jet fuel from materials such as tar sands, oil shale, coal or mixtures thereof.
Wide utilization of coal, oil shale and tar sands depends on the integrated mass production of products. The fluidized-bed reactor is generally considered to be the ideal solid processing reactor because of its high solid throughput of about 3,000 lbs./hr./sq.ft. bed area, especially when compared to the 400 lbs./hr./sq.ft. of bed area throughput for such reactors as the moving bed reactor.
However, past experience has shown that fluidized-bed reactors may not be an ideal reactor for handling coal, oil shale or tar sands because of the tendency of the e e materials to cake. Fluidized-bed reactors are unable to handle caking materials, and attempts to burn caking materials in a fluidized-bed reactor without inert matter resulted in the clinkering of the entire fluidized-bed. Many operational failures occurred in early coal pyrolysis products and these were also attributed to the caking problem.
Generally, there are two typical coals which are used for the United States Coal Standards, the Illinois No. 6 seam coal and the Pittsturgh No. 8 seam coal. The Illinois No. 6 coal has a free swelling index of 3 to 4, a high sulfur content (3% or more) and a high chlorine content (0.39%). The Pittsburgh No. 8 seam coal has a free swelling index of 8, a high sulfur content (3% or more) and a somewhat lower chlorine content of about 0.06%. Chlorine is a very corrosive element at high combustion temperature, and thus, Illinois No. 6 coal is best suited for liquid production, which is accomplished at lower combustion temperatures. It is the general consensus that fluidized-bed and moving-bed reactors are not adequate to handle caking coals such as the Illinois No. 6 seam coal and the Pittsburgh No. 8 seam coal.
Thus, there is a need in the art for a coal combustion reactor which is capable of handling coals, oil shales and tar sands which have a tendency to cake under typical combustion conditions in fluidized-bed reactors. There is also a need in the art for a reactor for utilizing coal, oil shale and tar sands which has a high throughput rate and thus allows mass production of desirable products from these materials.